Electric controller.



J. H. HALL.

ELECTRIC CONTROLLER. APPLICATION FILED 00130, I911. RENEWED MAY 25,1915.

Patented ajr. 14, 1916.

[LET/5,441.

Time

INVENTOR 2v 1 BY fi /1 Wo Arrows? UNITED STATES PAT NToEEIc v JAY H. HALL, or CLEVELAND, OHIO, assrenon 'ro THE ELECTRIC con'rnoLLEEAnn I MANUFACTURING COMPANY, or CLEVELAND, OHIO, a oonrons'rron or'onrojf' ELECTRIC CONTROLLER. I

figecification of Letters Patent.

Application filed October so, 19i1,seria1 No. amass. Renewed ma t5,'191 ,.;jssa1 no; 30,4ea1' To all whom it may concern:

Be it known that I, J A: H. HALL, a citizen of the United States, residing at Cleveland, in the county of Cuya-hoga and State of Ohio, have invented new and useful Improvements in Electric Controllers, of which the following is a specification.

My invention relates to automatic controllers for electric lnotors'wherein the operation of the resistance-controlling switches is governed by the current fiowing in the motor circuit.

It is one of the objects of my invention to provide a motor-controller having resistance-controlling switches energized by the current in the motor circuit, and adapted to lock open when the current is abovea cer tain predetermined limit and to operate when the current decreases below that limit, the said switches being further adjusted to lock out at difierentvalues of current in the motor circuit.

Referring to the accompanying drawing, Figure l is adiagrammatic viewembodying my invention; Fig. 2, a modification thereor; and Fig. 3, a curve showing the Values of current forlocking-out the successivelyclosing switches.

Referring to Fig. 1, S indicates a line switch, A the armature of the motor to be controlled, and F the series field thereof. Sections of starting resistance are shown at R, R, R which are controlled,respectively, by the switches S, S and S their respective operating windings 0, c and 0 being all in series in the motor circuit andenergized by the currenttherein. The switches S, S and S are of that type of switch described in Harry R. Canfields applications, Serial Number 583,000, filed September21, 1910, and Serial Number 604,331, filed J anuary 23, 1911, and in Eastwoods Patent, No.

1,040,292, granted October 8, 1912. In these justed to operate.

for the switch S These locking cut yalues are illustrated diagrammatically infFig. 3,:

Patented ama-491s.

wherein the ordinates represent current and the abscissae time. As shown',I',the lockmg out value'of the switch S, is higherthan I the locking out value'of the switch S which is higherthan T the looking out? value of the switch S The operation of this the armature A, the field F, the windings c c 0, and the resistance sections 'R;

controller is as follows: Closing the line switch S completes the motor circuit from the "positive through R R to thenegative. The current being .f

limited only by the resistance of the'circuit rises at once to its maximum'value' represented by I in Fig.3. Consequently, all the resistance switches are locked to the open position. After a while, due to the acceleration of the motor, the'current in the motorcircuit diminishes to the-value I, at which -'i the resistance switch S is adjusted toope'r-i, ate, whereupon the said switch closes its contacts and short-circuits i resistance section" i R, which causes another'rush of-current-in' the motor circuit, but asth'e speed of the motor increases'the current decreasesuntil' the speed issuch that thecurrentfalls to q the value I at 'whi'ch the switch S is*ad-- switch S will close 'its contacts, short-cir- At that moment' the J cuit the resistance section R and also short circuit the operating winding 0 of they switch S. which willdrop to the open position. The operation of the switch PS causes another rush of current in'the motor circuit which locks the switch S tothe open position, but'as" the motor accelerates the current decreases, andwhe'mit reachesithe value P, at which the switch S is adjusted to operate, the saidswitch will clo'se its 0on tacts, short-circuit the last-resistance section R and also the operating winding c? of 'the{ switch S which drops to the open position'pib Another rush of current flows 'inthe c'ircuit and the said current diminishesgradually to its normal load value The 'circuit'is- 'now traced from the positive through the armature of the motor A, the field F, and the operating winding 0 of the switch S to the negative. It will be seen that owing to the different value of the locking current of the switches S, S S the said switches will alwaysoperate in a proper sequence with a rapidity governed by the load on the motor.

To stop the motor, the switch S is opened, whereupon the motor circuit is opened, the winding 0 is deenergized, and the switch S drops to the open. position.

Referring now to Fig. 2, one contact of the switch S is connected directly to the negative as in Fig. 1, but the second contact, instead of being connected to the upper terminal of the winding 0 is connected to the lower terminal thereof. It follows that, when the switch S closes its contacts, it also short-circuits its own operating windin c andwould drop were it not for a hohIing winding H one end of which is connected to the positive and the other to the bridging piece of the switch S It follows that, when the switch S is closed, the holding circuit through the winding H is energized and the said switch maintained in the closed position. Except as to the action of the switch S just described, theoperation of the system shown on Fig. 2 is the same as that shown on Fig. 1.

It will he evident to those skilled a the art that my controller can be used for the control of a shunt motor, and that reversing switches may be provided incase it is necessary to reverse the rotation of the motor. I claim y 1. In a motor control system, a motor circuit, a motor, resistances therefor, switches for controlling said resistances adapted to close-in,a predetermined 'order, and wind ings for operating and'h'olding said switches closed, energized simultaneously and connected in series in the motoljjcircuit.

2. In a motor control system, a-"motor cir cuit, a motor, resistancesftherefor, switches for controlling said resistances, operating windings therefor all connected in series and a energized by the currentin the motor aircuit, and connections whereby eachswitch except the first to operate short-circuits the operating switch.

v In a motor control system, a motor circuit, a motor, resistances therefor, switches arranged to close in a definite order for controlling said resistances, operating windings therefor all connected in series and energized by theeiirrentinuthe motor circuit, and connections whereby each switch except the first to operate short-circuits the operating'winding of the next preceding switch.

winding of the next preceding.

the operating winding of the preceding .of October, A. D. 1911.

4. In an electric motor system, a motor, resistances therefor, resistance-controlling. switches, windings connected in series and energized simultaneously for closing said switches and holding them closed, and means including connections for closing the switches in automatic progression.

5. In an electric controller, a circuit, a resistance in the circuit, a series of switches for controlling the resistance, operating windings for the switches energized by current in the circuit and all connected in series with one another, each winding being deenergized by the closure of the succeeding switch, and connections for causing the switches to close in a-predetermined order.

'6. In an electric controller, acircuit, a, resistance, a plurality of switch-controlling windings, means for connecting the resistance and the windings in series in the circuit, and means including initially open switch contacts closable by the said windings for causing the said contacts to close in a predetermined order.

except the first toclose short-circuits a por-' tion of the resistance and deenergizes the operating winding'of the preceding switch in the series.

. 8. In an electric controller, a circuit, re-

ranged to close in a predetermined order for controlling the resistance, operating wmd series in the circuit, and connections wherebyeach switch except the first to operate short-circuits a portion of the resistance and switch,.leaving its own winding in the circuit.

Signed at Cleveland, Ohio, this 26th day JAY H. HALL.

Witnesses:

' R. H. BENNETT, H. M. DIEMER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ratents,

' Washington, D. 0.

' ings therefor, main contacts for connecting an the switch windings and the resistance in 90 Isistance therefor, a plurality of switches ar 

